> You have to pay the government rent in perpetuity.

You are paying the government rent in perpetuity for the services they provide, including enforcement of your property rights. If you wish to live on land without paying government rent, you will need to go to a place without effective government. Today, that would be Syria, parts of Sudan, or Mali as examples. I doubt you want to live in those places as a 1st world resident, but if you do, there's little stopping you.

It’s exactly the correct idea. If the value of your land rises as a positive externality, it only makes sense that you contribute some of that back to the society that effected the rise in the first place.

No it doesn't. You haven't realized any gains, therefore it's not just to tax you on that.

Vast majority are realizing their gains as rent. A land tax would just be taxing those gains before they can be recycled into the real-estate market. Perfectly just in that case.

If you're talking about an individual not using the land commercially - well theoretically the tax burden lowers the sale price. You don't pay both. At 100% land tax, the sale price would be zero. You pay only as you use the land. That also seems just to me.

Well I have news for you… governments are coming for unrealized gains, they will not care if the money is on hand, they’ll fire sell your property if you don’t get a loan to pay the taxes. It’s a mathematical inevitability. And by that I mean governments are going broke and will try to find ever more creative ways to raise money, and unrealized gains, tax normalization, is one of the bigger leavers.

Where I live, the government owns about 40% of the value of my labour. I have to rent my own body in perpetuity. Meanwhile my second biggest expense is a mortgage I pay for land that nobody created.

How much of the land value of your country do you currently own? A land value tax is likely to increase the amount of land you own (the profits of). I don't think US tracks land values as accurately as countries with some kind of land tax.

The alternative is unbounded compounding of wealth until all land is held by very few hands.

Paying taxes in perpetuity is what pretty much everyone does.

Not necessarily. It can be arranged so for owners with no income the tax accrues to the land and no cashflow is necessary until sale.

California and at least ten other states have programs for the elderly to defer paying property tax on their homestead and the heirs pay it.